EPC Ratings Explained — The A to G Scale

Every Energy Performance Certificate in the UK assigns a property a rating from A (most efficient) to G (least efficient). This rating is based on the property's Energy Efficiency Rating (EER) — a numerical score from 1 to 100. The higher the number, the more energy-efficient the property.

The A–G Rating Bands

Rating	Score Range	What It Means
A	92–100	Exceptionally efficient. Rare in existing homes — mostly new builds to the highest standard. Very low energy bills.
B	81–91	Highly efficient. Modern new builds and heavily retrofitted older properties. Annual energy costs well below average.
C	69–80	Above average. The incoming minimum standard for rental properties by 2030. Well-insulated with a modern heating system.
D	55–68	The most common rating in England and Wales. A typical 1950s–1990s house with some insulation and a gas boiler.
E	39–54	Below average. The current legal minimum for rental properties. Older properties with limited insulation.
F	21–38	Poor efficiency. Illegal to let without an exemption. High energy bills, typically pre-1930s construction.
G	1–20	Worst performing. Illegal to let. Often uninsulated solid-wall properties with outdated heating systems.

Current Rating vs Potential Rating

Every EPC shows two ratings: current and potential. The current rating reflects the property as it stands today. The potential rating shows what it could achieve if all recommended improvements were carried out.

For landlords, the gap between current and potential is particularly important — it shows how far the property could improve and at what cost. A property rated D with a potential of B, for example, has a clear upgrade pathway that may be achievable within the £10,000 cost cap.

What Rating Do Most UK Properties Have?

The average EPC rating in England and Wales is D (score around 60). The distribution looks roughly like this:

• A or B: ~15% of properties (mostly post-2010 new builds)
• C: ~30% of properties
• D: ~35% of properties — the largest single group
• E: ~14% of properties
• F or G: ~6% of properties

For the private rented sector, approximately 52% of properties are currently below EPC C — meaning over 2 million rented homes need upgrading before the 2030 deadline.

EPC Rating C — The 2030 Target

EPC C (score 69–80) is the incoming minimum standard for all privately rented properties in England and Wales by 1 October 2030. A typical EPC C property has:

• Adequate loft insulation (270mm+)
• Cavity wall insulation or well-insulated solid walls
• Double glazing throughout
• A modern condensing boiler or heat pump
• Low-energy lighting

For many landlords with D-rated properties, reaching C is achievable with targeted improvements costing £1,000–£4,000.

EPC Rating D — The Most Common Rating

EPC D (score 55–68) is where the majority of UK housing stock sits. These are typically 1950s–1990s properties with partial insulation and standard gas boilers. The gap from D to C usually requires loft insulation, cavity wall insulation, and LED lighting as a minimum.

EPC Ratings E, F, and G — Legal Implications for Landlords

EPC E (39–54) is the current legal minimum for rental properties. Landlords can legally let a property at E but not below. Properties rated F or G cannot be let without a registered exemption, and fines for non-compliance reach up to £30,000.

The New Metrics — Coming Late 2026

The single A–G band is being supplemented (and eventually replaced for new certificates) by four new metrics under the Home Energy Model:

1. Fabric Performance — how well the building retains heat (U-values, thermal bridging, airtightness)
2. Heating System — the efficiency of the installed heating system
3. Smart Readiness — the building's ability to adopt smart technology (smart meters, EV charging readiness, smart heating controls)
4. Energy Cost — estimated annual running costs

Current EPCs remain valid for their full 10-year lifespan. Only new certificates issued after the late 2026 launch will use the new format.